[RFC PATCH 5/7] qemu: add support to TDVF firmware loader

[Duan, Zhenzhong]

> -----Original Message-----
> From: Pavel Hrdina <phrdina at redhat.com>
> Sent: Friday, June 18, 2021 8:34 PM
> To: Duan, Zhenzhong <zhenzhong.duan at intel.com>
> Cc: libvir-list at redhat.com; Yamahata, Isaku <isaku.yamahata at intel.com>;
> Tian, Jun J <jun.j.tian at intel.com>; Qiang, Chenyi <chenyi.qiang at intel.com>
> Subject: Re: [RFC PATCH 5/7] qemu: add support to TDVF firmware loader
> 
> On Fri, Jun 18, 2021 at 04:50:50PM +0800, Zhenzhong Duan wrote:
> > TDX guest need a specific firmware TDVF to bootup, add a new element
> > in TrustDomain element for that purpose, like below:
> >
> > <TrustDomain type='tdx'>
> >    <policy>0x0001</policy>
> >    <loader>/path/to/TDVF-binary</loader>
> > </TrustDomain>
> 
> Looking into QEMU patches and if I understand it correctly this loader is
> supposed to be used instead of UEFI or BIOS?
Yes.

> If that's true I don't think it
> should be here as we already have XML bits to specify VM loader.
> 
> We could use something like this:
> 
>   <os>
>     <loader type='generic'>/path/to/TDVF-binary</loader>
>   </os>
> 
> Currently supported types are:
> 
>  - `rom` which is translated to
> 
>      -bios /path/to/bios.bin
> 
>  - `pflash` which is translated to
> 
>      -drive file=/path/to/uefi.fd,if=pflash,format=raw,...
> 
> And we could add a new type called 'generic', 'device', 'binary' or something
> else which would be translated to:
> 
>      -device loader,file=/path/to/TDVF-binary,...
> 
Thanks for your suggestion, the main reason is I see only TDX guest using firmware in such a special way,
So I move <loader> in TDX specific element <TrustDomain>. I'll change to <os>.<loader> if you think it's better.

Thanks
Zhenzhong